#include <linux/slab.h>
#include <linux/skbuff.h>
+/* Returns true if a gve_tx_pending_packet_dqo object is available. */
+static bool gve_has_pending_packet(struct gve_tx_ring *tx)
+{
+ /* Check TX path's list. */
+ if (tx->dqo_tx.free_pending_packets != -1)
+ return true;
+
+ /* Check completion handler's list. */
+ if (atomic_read_acquire(&tx->dqo_compl.free_pending_packets) != -1)
+ return true;
+
+ return false;
+}
+
+static struct gve_tx_pending_packet_dqo *
+gve_alloc_pending_packet(struct gve_tx_ring *tx)
+{
+ struct gve_tx_pending_packet_dqo *pending_packet;
+ s16 index;
+
+ index = tx->dqo_tx.free_pending_packets;
+
+ /* No pending_packets available, try to steal the list from the
+ * completion handler.
+ */
+ if (unlikely(index == -1)) {
+ tx->dqo_tx.free_pending_packets =
+ atomic_xchg(&tx->dqo_compl.free_pending_packets, -1);
+ index = tx->dqo_tx.free_pending_packets;
+
+ if (unlikely(index == -1))
+ return NULL;
+ }
+
+ pending_packet = &tx->dqo.pending_packets[index];
+
+ /* Remove pending_packet from free list */
+ tx->dqo_tx.free_pending_packets = pending_packet->next;
+ pending_packet->state = GVE_PACKET_STATE_PENDING_DATA_COMPL;
+
+ return pending_packet;
+}
+
+static void
+gve_free_pending_packet(struct gve_tx_ring *tx,
+ struct gve_tx_pending_packet_dqo *pending_packet)
+{
+ s16 index = pending_packet - tx->dqo.pending_packets;
+
+ pending_packet->state = GVE_PACKET_STATE_UNALLOCATED;
+ while (true) {
+ s16 old_head = atomic_read_acquire(&tx->dqo_compl.free_pending_packets);
+
+ pending_packet->next = old_head;
+ if (atomic_cmpxchg(&tx->dqo_compl.free_pending_packets,
+ old_head, index) == old_head) {
+ break;
+ }
+ }
+}
+
/* gve_tx_free_desc - Cleans up all pending tx requests and buffers.
*/
static void gve_tx_clean_pending_packets(struct gve_tx_ring *tx)
}
}
+/* Returns the number of slots available in the ring */
+static inline u32 num_avail_tx_slots(const struct gve_tx_ring *tx)
+{
+ u32 num_used = (tx->dqo_tx.tail - tx->dqo_tx.head) & tx->mask;
+
+ return tx->mask - num_used;
+}
+
+/* Stops the queue if available descriptors is less than 'count'.
+ * Return: 0 if stop is not required.
+ */
+static int gve_maybe_stop_tx_dqo(struct gve_tx_ring *tx, int count)
+{
+ if (likely(gve_has_pending_packet(tx) &&
+ num_avail_tx_slots(tx) >= count))
+ return 0;
+
+ /* Update cached TX head pointer */
+ tx->dqo_tx.head = atomic_read_acquire(&tx->dqo_compl.hw_tx_head);
+
+ if (likely(gve_has_pending_packet(tx) &&
+ num_avail_tx_slots(tx) >= count))
+ return 0;
+
+ /* No space, so stop the queue */
+ tx->stop_queue++;
+ netif_tx_stop_queue(tx->netdev_txq);
+
+ /* Sync with restarting queue in `gve_tx_poll_dqo()` */
+ mb();
+
+ /* After stopping queue, check if we can transmit again in order to
+ * avoid TOCTOU bug.
+ */
+ tx->dqo_tx.head = atomic_read_acquire(&tx->dqo_compl.hw_tx_head);
+
+ if (likely(!gve_has_pending_packet(tx) ||
+ num_avail_tx_slots(tx) < count))
+ return -EBUSY;
+
+ netif_tx_start_queue(tx->netdev_txq);
+ tx->wake_queue++;
+ return 0;
+}
+
+static void gve_extract_tx_metadata_dqo(const struct sk_buff *skb,
+ struct gve_tx_metadata_dqo *metadata)
+{
+ memset(metadata, 0, sizeof(*metadata));
+ metadata->version = GVE_TX_METADATA_VERSION_DQO;
+
+ if (skb->l4_hash) {
+ u16 path_hash = skb->hash ^ (skb->hash >> 16);
+
+ path_hash &= (1 << 15) - 1;
+ if (unlikely(path_hash == 0))
+ path_hash = ~path_hash;
+
+ metadata->path_hash = path_hash;
+ }
+}
+
+static void gve_tx_fill_pkt_desc_dqo(struct gve_tx_ring *tx, u32 *desc_idx,
+ struct sk_buff *skb, u32 len, u64 addr,
+ s16 compl_tag, bool eop, bool is_gso)
+{
+ const bool checksum_offload_en = skb->ip_summed == CHECKSUM_PARTIAL;
+
+ while (len > 0) {
+ struct gve_tx_pkt_desc_dqo *desc =
+ &tx->dqo.tx_ring[*desc_idx].pkt;
+ u32 cur_len = min_t(u32, len, GVE_TX_MAX_BUF_SIZE_DQO);
+ bool cur_eop = eop && cur_len == len;
+
+ *desc = (struct gve_tx_pkt_desc_dqo){
+ .buf_addr = cpu_to_le64(addr),
+ .dtype = GVE_TX_PKT_DESC_DTYPE_DQO,
+ .end_of_packet = cur_eop,
+ .checksum_offload_enable = checksum_offload_en,
+ .compl_tag = cpu_to_le16(compl_tag),
+ .buf_size = cur_len,
+ };
+
+ addr += cur_len;
+ len -= cur_len;
+ *desc_idx = (*desc_idx + 1) & tx->mask;
+ }
+}
+
+/* Validates and prepares `skb` for TSO.
+ *
+ * Returns header length, or < 0 if invalid.
+ */
+static int gve_prep_tso(struct sk_buff *skb)
+{
+ struct tcphdr *tcp;
+ int header_len;
+ u32 paylen;
+ int err;
+
+ /* Note: HW requires MSS (gso_size) to be <= 9728 and the total length
+ * of the TSO to be <= 262143.
+ *
+ * However, we don't validate these because:
+ * - Hypervisor enforces a limit of 9K MTU
+ * - Kernel will not produce a TSO larger than 64k
+ */
+
+ if (unlikely(skb_shinfo(skb)->gso_size < GVE_TX_MIN_TSO_MSS_DQO))
+ return -1;
+
+ /* Needed because we will modify header. */
+ err = skb_cow_head(skb, 0);
+ if (err < 0)
+ return err;
+
+ tcp = tcp_hdr(skb);
+
+ /* Remove payload length from checksum. */
+ paylen = skb->len - skb_transport_offset(skb);
+
+ switch (skb_shinfo(skb)->gso_type) {
+ case SKB_GSO_TCPV4:
+ case SKB_GSO_TCPV6:
+ csum_replace_by_diff(&tcp->check,
+ (__force __wsum)htonl(paylen));
+
+ /* Compute length of segmentation header. */
+ header_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (unlikely(header_len > GVE_TX_MAX_HDR_SIZE_DQO))
+ return -EINVAL;
+
+ return header_len;
+}
+
+static void gve_tx_fill_tso_ctx_desc(struct gve_tx_tso_context_desc_dqo *desc,
+ const struct sk_buff *skb,
+ const struct gve_tx_metadata_dqo *metadata,
+ int header_len)
+{
+ *desc = (struct gve_tx_tso_context_desc_dqo){
+ .header_len = header_len,
+ .cmd_dtype = {
+ .dtype = GVE_TX_TSO_CTX_DESC_DTYPE_DQO,
+ .tso = 1,
+ },
+ .flex0 = metadata->bytes[0],
+ .flex5 = metadata->bytes[5],
+ .flex6 = metadata->bytes[6],
+ .flex7 = metadata->bytes[7],
+ .flex8 = metadata->bytes[8],
+ .flex9 = metadata->bytes[9],
+ .flex10 = metadata->bytes[10],
+ .flex11 = metadata->bytes[11],
+ };
+ desc->tso_total_len = skb->len - header_len;
+ desc->mss = skb_shinfo(skb)->gso_size;
+}
+
+static void
+gve_tx_fill_general_ctx_desc(struct gve_tx_general_context_desc_dqo *desc,
+ const struct gve_tx_metadata_dqo *metadata)
+{
+ *desc = (struct gve_tx_general_context_desc_dqo){
+ .flex0 = metadata->bytes[0],
+ .flex1 = metadata->bytes[1],
+ .flex2 = metadata->bytes[2],
+ .flex3 = metadata->bytes[3],
+ .flex4 = metadata->bytes[4],
+ .flex5 = metadata->bytes[5],
+ .flex6 = metadata->bytes[6],
+ .flex7 = metadata->bytes[7],
+ .flex8 = metadata->bytes[8],
+ .flex9 = metadata->bytes[9],
+ .flex10 = metadata->bytes[10],
+ .flex11 = metadata->bytes[11],
+ .cmd_dtype = {.dtype = GVE_TX_GENERAL_CTX_DESC_DTYPE_DQO},
+ };
+}
+
+/* Returns 0 on success, or < 0 on error.
+ *
+ * Before this function is called, the caller must ensure
+ * gve_has_pending_packet(tx) returns true.
+ */
+static int gve_tx_add_skb_no_copy_dqo(struct gve_tx_ring *tx,
+ struct sk_buff *skb)
+{
+ const struct skb_shared_info *shinfo = skb_shinfo(skb);
+ const bool is_gso = skb_is_gso(skb);
+ u32 desc_idx = tx->dqo_tx.tail;
+
+ struct gve_tx_pending_packet_dqo *pending_packet;
+ struct gve_tx_metadata_dqo metadata;
+ s16 completion_tag;
+ int i;
+
+ pending_packet = gve_alloc_pending_packet(tx);
+ pending_packet->skb = skb;
+ pending_packet->num_bufs = 0;
+ completion_tag = pending_packet - tx->dqo.pending_packets;
+
+ gve_extract_tx_metadata_dqo(skb, &metadata);
+ if (is_gso) {
+ int header_len = gve_prep_tso(skb);
+
+ if (unlikely(header_len < 0))
+ goto err;
+
+ gve_tx_fill_tso_ctx_desc(&tx->dqo.tx_ring[desc_idx].tso_ctx,
+ skb, &metadata, header_len);
+ desc_idx = (desc_idx + 1) & tx->mask;
+ }
+
+ gve_tx_fill_general_ctx_desc(&tx->dqo.tx_ring[desc_idx].general_ctx,
+ &metadata);
+ desc_idx = (desc_idx + 1) & tx->mask;
+
+ /* Note: HW requires that the size of a non-TSO packet be within the
+ * range of [17, 9728].
+ *
+ * We don't double check because
+ * - We limited `netdev->min_mtu` to ETH_MIN_MTU.
+ * - Hypervisor won't allow MTU larger than 9216.
+ */
+
+ /* Map the linear portion of skb */
+ {
+ struct gve_tx_dma_buf *buf =
+ &pending_packet->bufs[pending_packet->num_bufs];
+ u32 len = skb_headlen(skb);
+ dma_addr_t addr;
+
+ addr = dma_map_single(tx->dev, skb->data, len, DMA_TO_DEVICE);
+ if (unlikely(dma_mapping_error(tx->dev, addr)))
+ goto err;
+
+ dma_unmap_len_set(buf, len, len);
+ dma_unmap_addr_set(buf, dma, addr);
+ ++pending_packet->num_bufs;
+
+ gve_tx_fill_pkt_desc_dqo(tx, &desc_idx, skb, len, addr,
+ completion_tag,
+ /*eop=*/shinfo->nr_frags == 0, is_gso);
+ }
+
+ for (i = 0; i < shinfo->nr_frags; i++) {
+ struct gve_tx_dma_buf *buf =
+ &pending_packet->bufs[pending_packet->num_bufs];
+ const skb_frag_t *frag = &shinfo->frags[i];
+ bool is_eop = i == (shinfo->nr_frags - 1);
+ u32 len = skb_frag_size(frag);
+ dma_addr_t addr;
+
+ addr = skb_frag_dma_map(tx->dev, frag, 0, len, DMA_TO_DEVICE);
+ if (unlikely(dma_mapping_error(tx->dev, addr)))
+ goto err;
+
+ dma_unmap_len_set(buf, len, len);
+ dma_unmap_addr_set(buf, dma, addr);
+ ++pending_packet->num_bufs;
+
+ gve_tx_fill_pkt_desc_dqo(tx, &desc_idx, skb, len, addr,
+ completion_tag, is_eop, is_gso);
+ }
+
+ /* Commit the changes to our state */
+ tx->dqo_tx.tail = desc_idx;
+
+ /* Request a descriptor completion on the last descriptor of the
+ * packet if we are allowed to by the HW enforced interval.
+ */
+ {
+ u32 last_desc_idx = (desc_idx - 1) & tx->mask;
+ u32 last_report_event_interval =
+ (last_desc_idx - tx->dqo_tx.last_re_idx) & tx->mask;
+
+ if (unlikely(last_report_event_interval >=
+ GVE_TX_MIN_RE_INTERVAL)) {
+ tx->dqo.tx_ring[last_desc_idx].pkt.report_event = true;
+ tx->dqo_tx.last_re_idx = last_desc_idx;
+ }
+ }
+
+ return 0;
+
+err:
+ for (i = 0; i < pending_packet->num_bufs; i++) {
+ struct gve_tx_dma_buf *buf = &pending_packet->bufs[i];
+
+ if (i == 0) {
+ dma_unmap_single(tx->dev, dma_unmap_addr(buf, dma),
+ dma_unmap_len(buf, len),
+ DMA_TO_DEVICE);
+ } else {
+ dma_unmap_page(tx->dev, dma_unmap_addr(buf, dma),
+ dma_unmap_len(buf, len), DMA_TO_DEVICE);
+ }
+ }
+
+ pending_packet->skb = NULL;
+ pending_packet->num_bufs = 0;
+ gve_free_pending_packet(tx, pending_packet);
+
+ return -1;
+}
+
+static int gve_num_descs_per_buf(size_t size)
+{
+ return DIV_ROUND_UP(size, GVE_TX_MAX_BUF_SIZE_DQO);
+}
+
+static int gve_num_buffer_descs_needed(const struct sk_buff *skb)
+{
+ const struct skb_shared_info *shinfo = skb_shinfo(skb);
+ int num_descs;
+ int i;
+
+ num_descs = gve_num_descs_per_buf(skb_headlen(skb));
+
+ for (i = 0; i < shinfo->nr_frags; i++) {
+ unsigned int frag_size = skb_frag_size(&shinfo->frags[i]);
+
+ num_descs += gve_num_descs_per_buf(frag_size);
+ }
+
+ return num_descs;
+}
+
+/* Returns true if HW is capable of sending TSO represented by `skb`.
+ *
+ * Each segment must not span more than GVE_TX_MAX_DATA_DESCS buffers.
+ * - The header is counted as one buffer for every single segment.
+ * - A buffer which is split between two segments is counted for both.
+ * - If a buffer contains both header and payload, it is counted as two buffers.
+ */
+static bool gve_can_send_tso(const struct sk_buff *skb)
+{
+ const int header_len = skb_checksum_start_offset(skb) + tcp_hdrlen(skb);
+ const int max_bufs_per_seg = GVE_TX_MAX_DATA_DESCS - 1;
+ const struct skb_shared_info *shinfo = skb_shinfo(skb);
+ const int gso_size = shinfo->gso_size;
+ int cur_seg_num_bufs;
+ int cur_seg_size;
+ int i;
+
+ cur_seg_size = skb_headlen(skb) - header_len;
+ cur_seg_num_bufs = cur_seg_size > 0;
+
+ for (i = 0; i < shinfo->nr_frags; i++) {
+ if (cur_seg_size >= gso_size) {
+ cur_seg_size %= gso_size;
+ cur_seg_num_bufs = cur_seg_size > 0;
+ }
+
+ if (unlikely(++cur_seg_num_bufs > max_bufs_per_seg))
+ return false;
+
+ cur_seg_size += skb_frag_size(&shinfo->frags[i]);
+ }
+
+ return true;
+}
+
+/* Attempt to transmit specified SKB.
+ *
+ * Returns 0 if the SKB was transmitted or dropped.
+ * Returns -1 if there is not currently enough space to transmit the SKB.
+ */
+static int gve_try_tx_skb(struct gve_priv *priv, struct gve_tx_ring *tx,
+ struct sk_buff *skb)
+{
+ int num_buffer_descs;
+ int total_num_descs;
+
+ if (skb_is_gso(skb)) {
+ /* If TSO doesn't meet HW requirements, attempt to linearize the
+ * packet.
+ */
+ if (unlikely(!gve_can_send_tso(skb) &&
+ skb_linearize(skb) < 0)) {
+ net_err_ratelimited("%s: Failed to transmit TSO packet\n",
+ priv->dev->name);
+ goto drop;
+ }
+
+ num_buffer_descs = gve_num_buffer_descs_needed(skb);
+ } else {
+ num_buffer_descs = gve_num_buffer_descs_needed(skb);
+
+ if (unlikely(num_buffer_descs > GVE_TX_MAX_DATA_DESCS)) {
+ if (unlikely(skb_linearize(skb) < 0))
+ goto drop;
+
+ num_buffer_descs = 1;
+ }
+ }
+
+ /* Metadata + (optional TSO) + data descriptors. */
+ total_num_descs = 1 + skb_is_gso(skb) + num_buffer_descs;
+ if (unlikely(gve_maybe_stop_tx_dqo(tx, total_num_descs +
+ GVE_TX_MIN_DESC_PREVENT_CACHE_OVERLAP))) {
+ return -1;
+ }
+
+ if (unlikely(gve_tx_add_skb_no_copy_dqo(tx, skb) < 0))
+ goto drop;
+
+ netdev_tx_sent_queue(tx->netdev_txq, skb->len);
+ skb_tx_timestamp(skb);
+ return 0;
+
+drop:
+ tx->dropped_pkt++;
+ dev_kfree_skb_any(skb);
+ return 0;
+}
+
+/* Transmit a given skb and ring the doorbell. */
netdev_tx_t gve_tx_dqo(struct sk_buff *skb, struct net_device *dev)
{
+ struct gve_priv *priv = netdev_priv(dev);
+ struct gve_tx_ring *tx;
+
+ tx = &priv->tx[skb_get_queue_mapping(skb)];
+ if (unlikely(gve_try_tx_skb(priv, tx, skb) < 0)) {
+ /* We need to ring the txq doorbell -- we have stopped the Tx
+ * queue for want of resources, but prior calls to gve_tx()
+ * may have added descriptors without ringing the doorbell.
+ */
+ gve_tx_put_doorbell_dqo(priv, tx->q_resources, tx->dqo_tx.tail);
+ return NETDEV_TX_BUSY;
+ }
+
+ if (!netif_xmit_stopped(tx->netdev_txq) && netdev_xmit_more())
+ return NETDEV_TX_OK;
+
+ gve_tx_put_doorbell_dqo(priv, tx->q_resources, tx->dqo_tx.tail);
return NETDEV_TX_OK;
}
+static void add_to_list(struct gve_tx_ring *tx, struct gve_index_list *list,
+ struct gve_tx_pending_packet_dqo *pending_packet)
+{
+ s16 old_tail, index;
+
+ index = pending_packet - tx->dqo.pending_packets;
+ old_tail = list->tail;
+ list->tail = index;
+ if (old_tail == -1)
+ list->head = index;
+ else
+ tx->dqo.pending_packets[old_tail].next = index;
+
+ pending_packet->next = -1;
+ pending_packet->prev = old_tail;
+}
+
+static void remove_from_list(struct gve_tx_ring *tx,
+ struct gve_index_list *list,
+ struct gve_tx_pending_packet_dqo *pending_packet)
+{
+ s16 index, prev_index, next_index;
+
+ index = pending_packet - tx->dqo.pending_packets;
+ prev_index = pending_packet->prev;
+ next_index = pending_packet->next;
+
+ if (prev_index == -1) {
+ /* Node is head */
+ list->head = next_index;
+ } else {
+ tx->dqo.pending_packets[prev_index].next = next_index;
+ }
+ if (next_index == -1) {
+ /* Node is tail */
+ list->tail = prev_index;
+ } else {
+ tx->dqo.pending_packets[next_index].prev = prev_index;
+ }
+}
+
+static void gve_unmap_packet(struct device *dev,
+ struct gve_tx_pending_packet_dqo *pending_packet)
+{
+ struct gve_tx_dma_buf *buf;
+ int i;
+
+ /* SKB linear portion is guaranteed to be mapped */
+ buf = &pending_packet->bufs[0];
+ dma_unmap_single(dev, dma_unmap_addr(buf, dma),
+ dma_unmap_len(buf, len), DMA_TO_DEVICE);
+ for (i = 1; i < pending_packet->num_bufs; i++) {
+ buf = &pending_packet->bufs[i];
+ dma_unmap_page(dev, dma_unmap_addr(buf, dma),
+ dma_unmap_len(buf, len), DMA_TO_DEVICE);
+ }
+ pending_packet->num_bufs = 0;
+}
+
+/* Completion types and expected behavior:
+ * No Miss compl + Packet compl = Packet completed normally.
+ * Miss compl + Re-inject compl = Packet completed normally.
+ * No Miss compl + Re-inject compl = Skipped i.e. packet not completed.
+ * Miss compl + Packet compl = Skipped i.e. packet not completed.
+ */
+static void gve_handle_packet_completion(struct gve_priv *priv,
+ struct gve_tx_ring *tx, bool is_napi,
+ u16 compl_tag, u64 *bytes, u64 *pkts,
+ bool is_reinjection)
+{
+ struct gve_tx_pending_packet_dqo *pending_packet;
+
+ if (unlikely(compl_tag >= tx->dqo.num_pending_packets)) {
+ net_err_ratelimited("%s: Invalid TX completion tag: %d\n",
+ priv->dev->name, (int)compl_tag);
+ return;
+ }
+
+ pending_packet = &tx->dqo.pending_packets[compl_tag];
+
+ if (unlikely(is_reinjection)) {
+ if (unlikely(pending_packet->state ==
+ GVE_PACKET_STATE_TIMED_OUT_COMPL)) {
+ net_err_ratelimited("%s: Re-injection completion: %d received after timeout.\n",
+ priv->dev->name, (int)compl_tag);
+ /* Packet was already completed as a result of timeout,
+ * so just remove from list and free pending packet.
+ */
+ remove_from_list(tx,
+ &tx->dqo_compl.timed_out_completions,
+ pending_packet);
+ gve_free_pending_packet(tx, pending_packet);
+ return;
+ }
+ if (unlikely(pending_packet->state !=
+ GVE_PACKET_STATE_PENDING_REINJECT_COMPL)) {
+ /* No outstanding miss completion but packet allocated
+ * implies packet receives a re-injection completion
+ * without a a prior miss completion. Return without
+ * completing the packet.
+ */
+ net_err_ratelimited("%s: Re-injection completion received without corresponding miss completion: %d\n",
+ priv->dev->name, (int)compl_tag);
+ return;
+ }
+ remove_from_list(tx, &tx->dqo_compl.miss_completions,
+ pending_packet);
+ } else {
+ /* Packet is allocated but not a pending data completion. */
+ if (unlikely(pending_packet->state !=
+ GVE_PACKET_STATE_PENDING_DATA_COMPL)) {
+ net_err_ratelimited("%s: No pending data completion: %d\n",
+ priv->dev->name, (int)compl_tag);
+ return;
+ }
+ }
+ gve_unmap_packet(tx->dev, pending_packet);
+
+ *bytes += pending_packet->skb->len;
+ (*pkts)++;
+ napi_consume_skb(pending_packet->skb, is_napi);
+ pending_packet->skb = NULL;
+ gve_free_pending_packet(tx, pending_packet);
+}
+
+static void gve_handle_miss_completion(struct gve_priv *priv,
+ struct gve_tx_ring *tx, u16 compl_tag,
+ u64 *bytes, u64 *pkts)
+{
+ struct gve_tx_pending_packet_dqo *pending_packet;
+
+ if (unlikely(compl_tag >= tx->dqo.num_pending_packets)) {
+ net_err_ratelimited("%s: Invalid TX completion tag: %d\n",
+ priv->dev->name, (int)compl_tag);
+ return;
+ }
+
+ pending_packet = &tx->dqo.pending_packets[compl_tag];
+ if (unlikely(pending_packet->state !=
+ GVE_PACKET_STATE_PENDING_DATA_COMPL)) {
+ net_err_ratelimited("%s: Unexpected packet state: %d for completion tag : %d\n",
+ priv->dev->name, (int)pending_packet->state,
+ (int)compl_tag);
+ return;
+ }
+
+ pending_packet->state = GVE_PACKET_STATE_PENDING_REINJECT_COMPL;
+ /* jiffies can wraparound but time comparisons can handle overflows. */
+ pending_packet->timeout_jiffies =
+ jiffies +
+ msecs_to_jiffies(GVE_REINJECT_COMPL_TIMEOUT *
+ MSEC_PER_SEC);
+ add_to_list(tx, &tx->dqo_compl.miss_completions, pending_packet);
+
+ *bytes += pending_packet->skb->len;
+ (*pkts)++;
+}
+
+static void remove_miss_completions(struct gve_priv *priv,
+ struct gve_tx_ring *tx)
+{
+ struct gve_tx_pending_packet_dqo *pending_packet;
+ s16 next_index;
+
+ next_index = tx->dqo_compl.miss_completions.head;
+ while (next_index != -1) {
+ pending_packet = &tx->dqo.pending_packets[next_index];
+ next_index = pending_packet->next;
+ /* Break early because packets should timeout in order. */
+ if (time_is_after_jiffies(pending_packet->timeout_jiffies))
+ break;
+
+ remove_from_list(tx, &tx->dqo_compl.miss_completions,
+ pending_packet);
+ /* Unmap buffers and free skb but do not unallocate packet i.e.
+ * the completion tag is not freed to ensure that the driver
+ * can take appropriate action if a corresponding valid
+ * completion is received later.
+ */
+ gve_unmap_packet(tx->dev, pending_packet);
+ /* This indicates the packet was dropped. */
+ dev_kfree_skb_any(pending_packet->skb);
+ pending_packet->skb = NULL;
+ tx->dropped_pkt++;
+ net_err_ratelimited("%s: No reinjection completion was received for: %ld.\n",
+ priv->dev->name,
+ (pending_packet - tx->dqo.pending_packets));
+
+ pending_packet->state = GVE_PACKET_STATE_TIMED_OUT_COMPL;
+ pending_packet->timeout_jiffies =
+ jiffies +
+ msecs_to_jiffies(GVE_DEALLOCATE_COMPL_TIMEOUT *
+ MSEC_PER_SEC);
+ /* Maintain pending packet in another list so the packet can be
+ * unallocated at a later time.
+ */
+ add_to_list(tx, &tx->dqo_compl.timed_out_completions,
+ pending_packet);
+ }
+}
+
+static void remove_timed_out_completions(struct gve_priv *priv,
+ struct gve_tx_ring *tx)
+{
+ struct gve_tx_pending_packet_dqo *pending_packet;
+ s16 next_index;
+
+ next_index = tx->dqo_compl.timed_out_completions.head;
+ while (next_index != -1) {
+ pending_packet = &tx->dqo.pending_packets[next_index];
+ next_index = pending_packet->next;
+ /* Break early because packets should timeout in order. */
+ if (time_is_after_jiffies(pending_packet->timeout_jiffies))
+ break;
+
+ remove_from_list(tx, &tx->dqo_compl.timed_out_completions,
+ pending_packet);
+ gve_free_pending_packet(tx, pending_packet);
+ }
+}
+
int gve_clean_tx_done_dqo(struct gve_priv *priv, struct gve_tx_ring *tx,
struct napi_struct *napi)
{
- return 0;
+ u64 reinject_compl_bytes = 0;
+ u64 reinject_compl_pkts = 0;
+ int num_descs_cleaned = 0;
+ u64 miss_compl_bytes = 0;
+ u64 miss_compl_pkts = 0;
+ u64 pkt_compl_bytes = 0;
+ u64 pkt_compl_pkts = 0;
+
+ /* Limit in order to avoid blocking for too long */
+ while (!napi || pkt_compl_pkts < napi->weight) {
+ struct gve_tx_compl_desc *compl_desc =
+ &tx->dqo.compl_ring[tx->dqo_compl.head];
+ u16 type;
+
+ if (compl_desc->generation == tx->dqo_compl.cur_gen_bit)
+ break;
+
+ /* Prefetch the next descriptor. */
+ prefetch(&tx->dqo.compl_ring[(tx->dqo_compl.head + 1) &
+ tx->dqo.complq_mask]);
+
+ /* Do not read data until we own the descriptor */
+ dma_rmb();
+ type = compl_desc->type;
+
+ if (type == GVE_COMPL_TYPE_DQO_DESC) {
+ /* This is the last descriptor fetched by HW plus one */
+ u16 tx_head = le16_to_cpu(compl_desc->tx_head);
+
+ atomic_set_release(&tx->dqo_compl.hw_tx_head, tx_head);
+ } else if (type == GVE_COMPL_TYPE_DQO_PKT) {
+ u16 compl_tag = le16_to_cpu(compl_desc->completion_tag);
+
+ gve_handle_packet_completion(priv, tx, !!napi,
+ compl_tag,
+ &pkt_compl_bytes,
+ &pkt_compl_pkts,
+ /*is_reinjection=*/false);
+ } else if (type == GVE_COMPL_TYPE_DQO_MISS) {
+ u16 compl_tag = le16_to_cpu(compl_desc->completion_tag);
+
+ gve_handle_miss_completion(priv, tx, compl_tag,
+ &miss_compl_bytes,
+ &miss_compl_pkts);
+ } else if (type == GVE_COMPL_TYPE_DQO_REINJECTION) {
+ u16 compl_tag = le16_to_cpu(compl_desc->completion_tag);
+
+ gve_handle_packet_completion(priv, tx, !!napi,
+ compl_tag,
+ &reinject_compl_bytes,
+ &reinject_compl_pkts,
+ /*is_reinjection=*/true);
+ }
+
+ tx->dqo_compl.head =
+ (tx->dqo_compl.head + 1) & tx->dqo.complq_mask;
+ /* Flip the generation bit when we wrap around */
+ tx->dqo_compl.cur_gen_bit ^= tx->dqo_compl.head == 0;
+ num_descs_cleaned++;
+ }
+
+ netdev_tx_completed_queue(tx->netdev_txq,
+ pkt_compl_pkts + miss_compl_pkts,
+ pkt_compl_bytes + miss_compl_bytes);
+
+ remove_miss_completions(priv, tx);
+ remove_timed_out_completions(priv, tx);
+
+ u64_stats_update_begin(&tx->statss);
+ tx->bytes_done += pkt_compl_bytes + reinject_compl_bytes;
+ tx->pkt_done += pkt_compl_pkts + reinject_compl_pkts;
+ u64_stats_update_end(&tx->statss);
+ return num_descs_cleaned;
}
bool gve_tx_poll_dqo(struct gve_notify_block *block, bool do_clean)
{
- return false;
+ struct gve_tx_compl_desc *compl_desc;
+ struct gve_tx_ring *tx = block->tx;
+ struct gve_priv *priv = block->priv;
+
+ if (do_clean) {
+ int num_descs_cleaned = gve_clean_tx_done_dqo(priv, tx,
+ &block->napi);
+
+ /* Sync with queue being stopped in `gve_maybe_stop_tx_dqo()` */
+ mb();
+
+ if (netif_tx_queue_stopped(tx->netdev_txq) &&
+ num_descs_cleaned > 0) {
+ tx->wake_queue++;
+ netif_tx_wake_queue(tx->netdev_txq);
+ }
+ }
+
+ /* Return true if we still have work. */
+ compl_desc = &tx->dqo.compl_ring[tx->dqo_compl.head];
+ return compl_desc->generation != tx->dqo_compl.cur_gen_bit;
}
projects / users / hch / configfs.git / commitdiff